Please use this identifier to cite or link to this item:
Author(s): Gomes, JRB
Sousa, EA
Gomes, P
Vale, N
Goncalves, JM
Pandey, S
Acree, WE
Ribeiro Da Silva, MDMC
Title: Thermochemical studies on 3-methyl-quinoxaline-2-carboxamide-1,4-dioxide derivatives: Enthalpies of formation and of N-O bond dissociation
Issue Date: 2007
Abstract: The standard molar enthalpies of formation of the 3-methyl-N-R-2- quinoxalinecarboxamide-1,4-dioxides (R = H, phenyl, 2-tolyl) in the gas phase were derived using the values for the enthalpies of combustion of the crystalline compounds, measured by static bomb combustion calorimetry, and for the enthalpies of sublimation, measured by Knudsen effusion, at T = 298.15 K. These values have also been used to calibrate a computational procedure that has been employed to estimate the gas-phase enthalpies of formation of the corresponding 3-methyl-N-R-2-quinoxalinecarboxamides and also to compute the first, second, and mean N-O bond dissociation enthalpies in the gas phase. It is found that the size of the substituent almost does not influence the computed N-O bond dissociation enthalpies; the maximum enthalpic difference is 5 kJ·mol-1. © 2007 American Chemical Society.
Subject: Química
Chemical sciences
Scientific areas: Ciências exactas e naturais::Química
Natural sciences::Chemical sciences
Document Type: Artigo em Revista Científica Internacional
Rights: openAccess
Appears in Collections:FCUP - Artigo em Revista Científica Internacional

Files in This Item:
File Description SizeFormat 
89120.pdf98.85 kBAdobe PDFThumbnail

This item is licensed under a Creative Commons License Creative Commons